Composition of matter.



UNITED STATES PATENT OFFICE.

STANLEY C. PETERS, 0F BRIDGEPORT, WASHINGTON.

COMPOSITION OF MATTER.

tains to make and use the same.

My invention relates to new and useful improvements in chemical compounds and more especially to investment compounds used by ewe1ers,opticians, dentists and the like in 'igh heat work such as solderin together of precious metals, such as gol silver, platinum'and the like and the object of my invention is to improve the efficiency of compounds of the above described character. These compounds are usually made up in powder form and when used are moistened with water to form a paste or putty which is then placed around whatever metal or metals which are to be exposed to the heat. With the com ound of this class now in the market it is a solutely essential that the investment so made'be exposed to the air for a certain length of time to permit it to set before exposing it to the flame.

A further ob'ect of my invention therefore is to provi e a compound which in use, may be immediately ex JOSBd to the flame, thus avoiding loss of va uable time.

My improved compound is made up of the following in 'redients, which are preferably mixed. in the proportions stated:

I Fire clay 287 grains.

Fullers earth 243 v Carbonate of magnesia 31 Sulfate of sodium 60 Pulverized mica -r 12 Ground asbestos 336 Borax 10 Specification of Letters Patent.

Application filed August 3, 1911. Serial No. 642,198.

Patented Aug. 1.3, 1912.

The fire clay which need be only com-' mercially pure is dried and then round to a powder and the sulfate of so ium and mica are also ground to a powder. These three ingredients are then mixed with the fullers earth, carbonate of magnesia and pulverized borax. The ground asbestos is then slowly added and throughly mixed when the compound is ready for use, the proportions above given being sullicient to form 979 grains of finished product. In use the compound so formed is mixed with a small amount of water to form a paste of putty like consistency and then employed in the manner well known. to them-t, with the 6X08)tl()l1 that the investment formed therewiti need not be exposed to the air for any length of time before applying the heat of the flame.

It will be understood that I do not wish in any way to limit myself to the exact proportions above given, as said proportions may be slightly varied to adapt the compound for use with various metals.

To obtain the best results the fullers earth, carbonate of magnesia, asbestos and borax should all be pure while the fire clay, sulfate of sodium and mica need only be commercially pure.

What I claim is A composition of the above described character, comprising a mixture of fire clay, fuller-s earth, carbonate of magnesia, sulfate of sodium, pulverized mica, ground asbestos, and pulverized borax.

In testimony whereof, I allix my signature, in presence of two witnesses.

STANLEY O. PETERS.

Witnesses:

I. T. MAIIANEY, JOHN JOHNSON. 

